Detailed Description

A wrapper class for a sparse direct LU decomposition on parallel blocks for Trilinos matrices. When run in serial, this corresponds to a direct solve on the matrix.

The AdditionalData data structure allows to set preconditioner options.

Note that a parallel application of the block direct solve preconditioner is actually a block-Jacobi preconditioner with block size equal to the local matrix size. Spoken more technically, this parallel operation is an additive Schwarz method with an exact solve as inner solver, based on the (outer) parallel partitioning.